When I ask well-traveled, non-cruisers what kind of ship they would consider for their first voyage, most say “small” and “casual.”

Yet if a company proposed to start a cruise line with new, small ships for 300 or fewer passengers, investors would be hard to find. Why? Because cruise experts say that they could not charge a rate high enough to pay for the cost of building a small ship.

So, there is irony in one of the latest success stories in the vacation industry. Windstar Cruises is carving out a popular niche with a growing fleet of small ships that carry 312 or fewer passengers. The key: Windstar’s billionaire owner is buying all of his ships second-hand.

In May, Windstar showed off its latest addition, the 212-passenger Star Pride. The ship, formerly Seabourn Pride, is cruising in the Mediterranean this summer before heading to Dubai and Singapore in November.

By this time next year, Windstar will own and operate six refurbished small ships that once were owned by brands of Carnival Corp., all built before 1991 and later sold as underachievers.

In three years, Windstar has moved from being a floundering cruise line, with three somewhat faded sailing ships and an owner in bankruptcy, to an energetic company with pretensions, and without debt. In 2011, Windstar was bought at a bargain price by Xanterra Parks and Resorts, which is privately controlled by Philip Anschutz, a man with deep pockets and an acumen for improving struggling enterprises.

Windstar’s president, Hans Birkholz, spent $18 million to spiff up the three sailing ships — Wind Surf (312 passengers), Wind Spirit (148) and Wind Star (148) — that were part of Carnival’s Holland America Line until 2007. Then, Birkholz bought the three aging 212-passenger, motor-driven ships from Carnival’s Seabourn, a luxury cruise line that now is operating new, larger ships.

Star Pride was christened into the Windstar fleet in Barcelona after 18 days in dry dock, where, said a Windstar executive, workers applied enough white paint that the ship probably gained a few pounds. Teak decks were scrubbed. Wood, furnishings, upholstery, lighting and wall coverings were changed, as Windstar aims to make the power yachts look more like the sailing ships that draw a loyal group of frequent cruisers.

The reworked Pride is airier, warmer and more contemporary than it was during its Seabourn days. Workers ripped out walls and redesigned the ship’s restaurant (AmphorA), main lounge (Compass Rose), forward observation lounge (Yacht Club) and an outdoor gathering spot, the Star Bar.

While the Star Pride was ready for cruising in May, it is not yet a finished product because Windstar is guiding the three-ship refurbishing process the way a sailing vessel approaches a new destination — deliberately, testing the waters.

Birkholz made sure that all the passengers on the first Star Pride cruise out of Barcelona were past Windstar guests, and he chatted with them for five days on the voyage to Rome, as the ship stopped in such delightful ports as Sete and Sanary-sur-Mer, France; Monaco; Portofino, Italy; and Portoferraio on the island of Elba. Birkholz then called a one-hour meeting with passengers on the final day to ask and answer questions about what they liked and didn’t like.

Changes yet to come on the Pride — and on the two other Seabourn ships when they join the fleet in 2015 — include a decision on the tiny, top-deck swimming pool that seems cramped and a waste of space on such a small vessel, as well as building additional dining spaces.

Veranda, the high, aft-end dining room that serves breakfast and lunch, becomes an intimate fine dining room called Candles each evening. It will be enlarged, perhaps at the expense of the pool. Windstar executives also are deciding on a location for a casual dining area for burgers, or something similar, in the evenings for passengers who want a choice beyond room service or sitting through several-course dinners in AmphorA or Candles.

As the transition continues, the biggest question that Windstar executives expect is a comparison between the cruise line’s ships with sails and the power yachts without — Seabourn Spirit will become Star Breeze in April 2015, and Seabourn Legend will become Star Legend in May 2015.

“We are known for our sails,” said Birkholz, but Windstar will offer a similar private yacht experience on the ships without sails. There are trade-offs, he said.

Power yachts can go faster, offering itineraries of greater distances, though he does not anticipate itineraries that require a full day at sea.

Power yachts also offer larger cabins (277 square feet compared to 188 square feet on the two smaller sailing yachts), the luxury of a bathtub, walk-in closet, and for many cabins a French balcony that opens for sea air. In the cruise business, the power yacht cabins are all called suites because they have a separate sitting area that can be curtained off from the bedroom. Six actual suites range from 400 to 575 square feet, with private verandas.

There may be additional ships in Windstar’s future, but they will be small, and probably not new.

“Economics do not favor new builds for yacht-size ships,” said Birkholz. “Sub-300 passengers is our marketplace. We fish where the fish are.”

David Molyneaux writes monthly about cruising. He is editor of TheTravelMavens.com